Use PublicKeyData as super trait for SigningKey

Author: djc

rcgen/src/crl.rs

@@ -25,8 +25,11 @@ use crate::{
 /// struct MyKeyPair { public_key: Vec<u8> }
 /// #[cfg(not(feature = "crypto"))]
 /// impl SigningKey for MyKeyPair {
-///   fn public_key(&self) -> &[u8] { &self.public_key }
 ///   fn sign(&self, _: &[u8]) -> Result<Vec<u8>, rcgen::Error> { Ok(vec![]) }
+/// }
+/// #[cfg(not(feature = "crypto"))]
+/// impl PublicKeyData for MyKeyPair {
+///	  fn der_bytes(&self) -> &[u8] { &self.public_key }
 ///   fn algorithm(&self) -> &'static SignatureAlgorithm { &PKCS_ED25519 }
 /// }
 /// # fn main () {

rcgen/src/key_pair.rs

@@ -523,7 +523,7 @@ impl PublicKeyData for KeyPair {
 			KeyPairKind::Ed(kp) => kp.public_key().as_ref(),
 			#[cfg(feature = "crypto")]
 			KeyPairKind::Rsa(kp, _) => kp.public_key().as_ref(),
-			KeyPairKind::Remote(kp) => kp.public_key(),
+			KeyPairKind::Remote(kp) => kp.der_bytes(),
 		}
 	}
 
@@ -658,15 +658,9 @@ pub enum RsaKeySize {
 ///
 /// Trait objects based on this trait can be passed to the [`KeyPair::from_remote`] function for generating certificates
 /// from a remote and raw private key, for example an HSM.
-pub trait SigningKey {
-	/// Returns the public key of this key pair in the binary format as in [`KeyPair::public_key_raw`]
-	fn public_key(&self) -> &[u8];
-
+pub trait SigningKey: PublicKeyData {
 	/// Signs `msg` using the selected algorithm
 	fn sign(&self, msg: &[u8]) -> Result<Vec<u8>, Error>;
-
-	/// Reveals the algorithm to be used when calling `sign()`
-	fn algorithm(&self) -> &'static SignatureAlgorithm;
 }
 
 #[cfg(feature = "crypto")]

rcgen/tests/webpki.rs

@@ -14,7 +14,8 @@ use webpki::{
 };
 
 use rcgen::{
-	BasicConstraints, Certificate, CertificateParams, DnType, Error, IsCa, KeyPair, SigningKey,
+	BasicConstraints, Certificate, CertificateParams, DnType, Error, IsCa, KeyPair, PublicKeyData,
+	SigningKey,
 };
 use rcgen::{CertificateRevocationListParams, RevocationReason, RevokedCertParams};
 #[cfg(feature = "x509-parser")]
@@ -318,17 +319,19 @@ fn from_remote() {
 	struct Remote(EcdsaKeyPair);
 
 	impl SigningKey for Remote {
-		fn public_key(&self) -> &[u8] {
-			self.0.public_key().as_ref()
-		}
-
 		fn sign(&self, msg: &[u8]) -> Result<Vec<u8>, rcgen::Error> {
 			let system_random = SystemRandom::new();
 			self.0
 				.sign(&system_random, msg)
 				.map(|s| s.as_ref().to_owned())
 				.map_err(|_| Error::RingUnspecified)
 		}
+	}
+
+	impl PublicKeyData for Remote {
+		fn der_bytes(&self) -> &[u8] {
+			self.0.public_key().as_ref()
+		}
 
 		fn algorithm(&self) -> &'static rcgen::SignatureAlgorithm {
 			&rcgen::PKCS_ECDSA_P256_SHA256